<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <button id="ldh">罗永浩</button>
    <button id="zxy">张学有</button>
    <img src="images/ldh.jpg" alt="刘德华">
    <script>
        // 修改元素属性
        // 1.获取元素
        var ldh = document.getElementById('ldh');
        var zxy = document.getElementById('zxy');
        var img = document.querySelector('img');
        // 2.注册事件  处理程序
        zxy.onclick = function(){
            img.src = 'images/zxy.jpg';
            img.title = '张学友';
        }
        ldh.onclick = function(){
            immg.src = 'images/ldh.jpg';
            img.title = '刘德华';
        }
    </script>
    
</body>
</html>